It is today common with transactions initiated and performed via e.g. Internet. Further, with mobile phones or similar devices it is today possible to perform transactions and related actions through data communication via wireless communication. This provides for a very neat way of performing secure transactions, by always having an electronic authentication device at hand, which could be used as a secure wallet/bank solution. However, this also provides for a variety of ways to manipulate the transaction systems in order to fraud one or both of the parts in a transaction.